Estudos de condutividade hidráulica em solos com diferentes teores de sódio trocável.

Abstract

An experiment was conducted under laboratory conditions to study the effect of the Sodium Exchangeable Percentage on the hydraulic conductivity of a saturated soil. For this, undisturbed samples of loamy-sand soil were saturated in Na2C03 solutions during 08 (eigth) days, to obtain Sodium Exchangeable Percentages between 4,8% and 64,1%. The hydraulic conductivity of the soil samples were measured on a constant hydraulic head permeameter and calculated through de Darcy's law equation. It was found a decrease of the hydraulic conductivity, with the Percentage of Exchangeable Sodium in the soil, reaching a reduction as great as 98% with the maximum Exchangeable Sodium (64,1%) when compared with the conductivity measured in normal soils. This fact was atribuited to the dispersion phenomenom of the soil particles wich probably blocked the porous of the soil, diminishing the capacity of them this to conduct water. The greater the Sodium Exchangeable Percentage in the soil the greater the dispersion and consequently smaller the hydraulic conductivity.